JP2942486B2 - Method and apparatus for free preview of communication network services - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cable television can receive the service for a fee, satellite TV
With respect to communication networks such as John and computer networks, in particular, prior to purchasing an offering of an individual program (eg, a movie program), the
The present invention relates to a method and apparatus for providing a free preview that can be watched for free only for a time .

[0002]

2. Description of the Related Art Cable television and satellite television, which can receive video services for a fee, are well known. Also, CompuServe, Prodigy,
Others are known that have access to America Online, Dialogue information services, databases, banking and shopping services, and can also communicate via e-mail. Conventionally,
Some communication networks have provided services on a free trial basis. For example, if a viewer orders a movie to watch for a fee,
In a pay-as-you-go television movie, viewers can buy
Before requesting , the first five minutes or so of the movie could be watched on a preview basis. Such previews were limited during a predetermined time interval at the start of the movie. Freeze at other times during the movie
No reviews were available .

The ability to provide a limited free preview at any time (ie, at any time) during the broadcast of a service (eg, a movie) is a consumer standing.
In terms of location, it is desirable. Watch for video services
Viewers only at the start of a program that is not convenient for viewers
Try to force a preview or even push it
Will not do . But using the service
Free preview with time limit at any time while you are
Providing is, from the perspective of a service provider, full of danger. Especially at any time to service
Making free preview available means that illegal viewers or "pirates" can break the security of the signal and use all services without paying a fee
Can be functional .

[0004] Time limit at any time during service provision
It may be advantageous to provide a method and apparatus that allows for the use of a free preview with a tag . Further, it may be advantageous to provide a method and apparatus that does not readily benefit outlaws or pirates. Such a method and apparatus is described in " Any Time Free Preview (AFP) (any
time free preview) ” , ie service at any time
Giving you the flexibility to preview in the meantime,
Signal security should be maintained. It may also be advantageous to provide a method and apparatus that allows a viewer to switch between one or more AFPs (each AFP is associated with a separate service) and a native program. Each AFP may be limited to its own specific maximum AFP time interval . Such systems, always must be secret protection, it must be prevented that the viewer Furipu review above maximum time interval which is provided to a particular service is obtained. The present invention provides a method and apparatus having the above-mentioned and other advantages.

[0005]

SUMMARY OF THE INVENTION The method of the present invention provides video services to consumers over an information network. The video service is a program epoc
h) provided on a pay-as-you-go basis. The program epoch is a program
(Or the maximum time allocated to the video service)
This is an extension of the sports program
Considering the extended time interval of the program by
Can be set longer than the time interval between the start and end of
You. Program epochs, that is, assigned to video services
In the maximum time interval, a portion of the video service is
Review can be fixed time intervals (fixed period) are included
You. Consumers, without buying a video service, during this fixed time interval, at any time, for up to <br/>-flops review time interval not shorter than the fixed time interval, to preview a portion of a video service Can be. In other words, consumers
You can qualitatively preview a part of the video service
Between, up to a maximum preview time interval during a fixed time interval
Limited to This maximum-flops review time interval (maximumpre
view dulation) is suitably, is protected by the secret protection method using encryption (cryptographically secure manner). In particular, between the unused-flops review time that is left to the consumer
A record indicating the amount of the interval is maintained in a cryptographically secure manner and the maximum preview time interval during a fixed time interval
Preview a portion of the video service
-It is made possible . In addition, the fixed time interval in which a part of the video service can be previewed is the same as the data for identifying whether or not a specific service can be received.
Suitably, it maintained secret protection method using encryption.

[0006] In a preferred embodiment, the method of the present invention comprises the steps of:
After previewing a portion of the video service,
Purchase this video service for viewing during the group epoch.
Including the step of allowing entry . Also, in the preferred embodiment, the program epoch is defined as multiple working key epochs (WKE) (ie, when multiple working keys are used).
Interval) . These WKE are counted and this total
Use cryptography that the number is authorized to use
Is confirmed . Count is allowed to use this confirmation is used to measure the maximum flop review time interval described above.

[0007] The method further comprises the step of maintaining a record of the service that the consumer previewed during a previous program epoch. Consumers may be able to access the current turn during a previous program epoch.
Preview all the service parts in the group epoch
If this happens, the consumer will be
Up review of its services is prohibited. This consumer, to prevent step-by-step recording to continuous Furipu review for viewing by accumulating full-length movies or other programs. Consumers preview during previous program epoch
Record over to had service is maintained by the private <br/> protection method using encryption.

[0008] In the illustrated embodiment, it flops of view that can be bidet
To maintain at the same time o service active record the up to N
Can be . Each record, purchase represents a been up review available video services purchased by a consumer recording or consumers of up review record representing video services <br/> scan chosen for flops review Consists of either. Expiration of active records of flop Les views <br/> over possible video services (or
The extinction) is prevented until the program epoch of the video service represented by the record ends. This expiration time is controlled by an expiration timer. Alternatively, the expiration of this record is prevented by providing each record with a fixed minimum recording time interval (eg, several hours). Fixed the minimum recording time interval, Furipu review possible longest-bi
Longer than video service.

Further, the method of the present invention also erase any flop Les views <br/> over recording, represented by the preview record
Until the epoch of the video service ends, prevent
Including the step of performing In the illustrated embodiment, up review record,
When the consumer purchases the video service represented by the preview record , the video service is changed to a purchase record. The purchase record due to this change cannot be changed. In such an embodiment, except that the preview record is erased by changes to changes allowed purchase records, also erasing any flop review recording, video services <br/> scan represented by this preview record It is prevented until the program epoch ends.

[0010] When all of the flops of viewable video service of the N recording is active always, additional flops of view of the consumer is rejected. However, up review record is overwritten with the purchase record, the consumer, bi-
You can still buy video services. Preferably, it is overwritten after the preview recording. When flop review record is opened, to consumers, informing the amount of unused preview time remaining in the corresponding video service.

[0011] device of the present invention provide up review of purchasable services through a communications network. First means processes data received from the communication network. This data includes: (i) identifying the services that can be purchased, (ii) identifying the time intervals (epochs) at which the services are provided, (iii) indicating whether the services can be previewed, (iv) consumers who is permitted to use to provide data necessary for generating a key for that can be served or flop review thereof. Second means, first when it is possible flop review of service 1
Respond to the means. Second means, when the flop review is allowed, the epoch (i.e., time interval) fixed time during
Give a separation . During the fixed time interval, at any time during the up-flops review time interval shorter than the fixed time interval, to allow the consumer a portion of the service is up review, the first and second means, User interfaces work together. With this user interface, consumers can also purchase services. After purchasing a flop review and in service, there is a means responsive to the first means for decoding the service.

The apparatus of the present invention uses encryption (ie,
Chi, was used encryption) further comprising means for protecting a maximum up review time interval secret protection method. The device of the present invention maintains the record in a secret protection method using encryption,
Instructing up amount of review time unused left to the consumer who can view the service during a fixed time interval.

[0013] means are provided for maintaining at the same time the flops of view services that can be active for the serial <br/> record up to N.
Each record, purchase represents a previewable service that has been purchased by a consumer recording or consumers consists flop review record representing the selected service to the flop Les views <br/> over. The expiration of the active record of flops review available services, until the program epoch service represented by this recording is completed, the means for preventing is provided.
Furthermore, erasure of any preview record until the program epoch service represented by the flop-les-bi <br/>-menu recording is completed, the means for preventing is provided. In the illustrated embodiment, in purchase by the consumer of the service represented by the flop review record, means for changing the preview record in the purchase record provided. The purchase record provided by this changing means cannot be changed. Preview recording
But, except in the case that has been changed to not be changed purchase records, Izu
Also erase the record of flops of view record, until the program epoch of service represented I <br/> by the this preview recording is finished,
Is prevented.

[0014] The apparatus of the present invention, all of the N-flops review services that can be recorded at any time when it is active,
Consumers respect, further comprising means for rejecting any flop review or flop review available services. Further, the means for informing the flop review amount of time unused left in each of the service to the consumer is provided.

In the illustrated embodiment, the epoch (ie, time interval) at which a service is provided is determined by a number of working
Key epoch (ie, when multiple working keys
Interval) . Use the counting of the working key epoch, maximum-flops review time interval of the above can be given. This count must be authorized for use
Is confirmed using cryptography. Using the solid <br/> constant time interval to allow up review, at least the encryption portions of the data indicating whether a preview of the service is available
Means are provided for confirming that the use has been permitted .

[0016]

Figure 1 DETAILED DESCRIPTION OF THE INVENTION is a block diagram of a decoding portion of a satellite or cable television receiver of the digital type. Encrypted services (eg, premium television services)
ce)) is input to the terminal 10. Configure this service
Bitstreams already when inputted into the terminal 10, using conventional techniques, is received from the communication channel is modulated and transmitted over a communication channel. Encrypted service is decrypted by the decryption processor 12, the output of the decoding processor 16
Thus, a clean signal is given.

The decoding processor, a conventional decoding ski <br/> beam, for example, Giruhauzen (Gilhousen) et al., U.S. Patent No. 4,613,901 (entitled selective remote descrambling and scrambling of television signals Signal Encryption and Distribution System for Control
Distribution System for Controlling Scrammbling an
d Selective Remote Descrambling of Television Sign
als)) or US Patent No. 486461 to Bennett et al.
No. 5 (entitled: Play of the secret protection key by using a key generation data distribution (Reproduct of Secure
keys By Using Distributed Key Generation Data))
To be used. To decode the signal input to the decoding <br/> processor via the terminal 10, the condensate
The encryption processor requires a working key (WK). Working key is input / output (I / O) terminal 3
0 is generated by the security processor 20 in response to a control signal received via the 0. Firmware to be used for secret protection processor is stored in ROM24. The security processor also has RAM in conventional specifications
22 is provided. The protected portion of the RAM 22 is a monthly key (mont
hly key) to hold a unit specific key and / or seed.

The user interface 26 is a television
The viewer can select a service to be viewed on John (TV) 28. Users, pre-order or number
Another specific purchases (e.g., usage-based), then <br/> is authorized to use the service to be received a service selected by the secret protection processor 20, a switch 18
In operation , the decoded output 16 is transmitted to the decoding processor 12.
To the TV 28 via the user interface 26. Otherwise, the user interface and the TV send the encrypted signal to line 14 and switch 1
8 only.

A typical key hierarchy is shown in FIG. Return
Program flops No. function 44, via the terminal 40, the encrypted
Key (or program pre-key)
key) ) and receives a monthly key via terminal 42. The program pre -key is unique for each encrypted program work (eg, a television program) and is available for decryption. The monthly key is changed periodically, for example, once a month. The decryption function 44 provides an encrypted program
It decrypts the Les key, given the program pre-key, this program
The pre -key is used as one input of the one-way function 48. Other inputs to the one-way function 48 are various program attributes (or program attributes ) (including access requirements ) for the corresponding program. You must meet this access requirement to get permission to watch the program. The program attributes are input via terminal 46, the one-way function processes the program pre-key and program attributes, the program key
Output (or program key ) . One-way function 4
Broadcasting key output from the 8, it is used as one input to another one-way function 52, the one-way function 52, the terminal 5
Through 0 receives the Initiation vector <br/> le represented by time (initiation vector) (IV). A one-way function 52 processes the program key and the initiation vector, which generates the working keys required by the decryption processor 12 (FIG. 1) and permits the use of the service.
Decoding <br/> the selected service by a variable user. Other descriptions of the generation of various keys, including working keys (given in the "keystream"), can be found in the aforementioned Bennett et al. Patent.

FIG. 3 is a diagram of an initiation vector input to terminal 50 of one-way function 52. Ini
The situation vector 60 starts at time = I and runs until time = J, for example, a few weeks, at which time the count is reset. A plurality of program epochs (PE ₁ to PE _n ) are generated on the time axis represented by the vector 60. Each program epoch is of different length and is associated with one program offering .

FIG. 4 shows one program epoch.(At 70
Show)FIG. The epoch starts at time 72,
It ends at time 78. AFP boundaries before the end of the epoch
74 andProgram boundaries (orProgram boundary)There are 76.
Start of epochtimeTime between 72 and AFP boundary 74while
SeparationIs a part of the programLesBy view systemViewBecause
Fixed, fixed time during program epochCorresponding to the interval. this
Fixed timeDuring the interval, Shows up to AFP timeintervalUp to 82
Only duringLesViewable. Arrow 84 in FIG.
AFP is the given maximum AFP time, as shown at 86interval
Up to “t”Until the maximum AFP time interval "t"
If,Either from the start of the epoch to the AFP boundary
Even in timeViewbe able to. Allowed pretend
Viewers can see some part of the preview time,
Switch again to watch the rest
Up to AFP timeinterval82 is working
・ Maintained as key count,With this count, the maximum AF
P time interval decreases, available AFP time intervalWaste
Be done.That is, as described below, the maximum AFP time
The number of working keys given to the
When the count decreases to zero, the AFP boundary 74
AFP will not be available even during this time. Also, the maximum AFP
The number of a given number of working keys given in the time interval
Even if AFP boundary 74 has passed even if is not zero
Cannot be previewed.

[0022] has requested the <br/> up review of the program during a fixed time interval that you can preview (or purchased) utilization of services
A working key is generated for the authorized subscriber during the program epoch. As shown in FIG. 4, the program epoch is composed of a plurality of working key epochs (WKE) (that is, a plurality of working key epochs).
(Division) divided by 80. For example, the working key epoch may occur at a rate of 8 WKEs per second, or other intervals as desired for what is given to the system. WKE
Can provide a means for maintaining the integrity of the AFP boundary 74. In the preferred embodiment, AFP boundary represents a boundary, the value of WKE, any time <br/> between (The anytime) Furipu review of beyond this boundary is not permitted. This parameter specifies the program attribute used to generate the program key.
Inclusion of this in the sexuality allows for free preview
Confirmation of permission is made . Maintaining and calculating AFP boundaries
This will be described in detail below with reference to FIGS.

Program boundary 76 is a predicted program end time at which the program provided during the program epoch will end. The end of the epoch 78, program boundary 78 (that
Extended beyond the original end time scheduled for the program)
This addresses the possibility of a program continuing beyond the length of the original time interval scheduled for the program.
You . For example, if a program is interrupted by breaking news, the end time of the program may be extended. Similarly, since it is impossible to accurately predict the end of the sports game, by extending the program boundaries in the program epoch, it may be necessary to Remedy the game to rush into overtime.

[0024] According to the present invention, Furipu review is, AF
After the P boundary no permission is granted. Therefore, the AFP boundary 74
And during a portion of the program between the epoch end time 78, Furipu review can not be obtained. The reason for setting the AFP boundary is to protect against the intrusion of Pirates who try to get programs or services for free using AFP. In particular, the pirate may attempt to change the end time of the program epoch to get free service. However, this does not mean that the AFP boundary has been granted, as described above.
The value has been confirmed to be
Since the review is not available, not a help to take the continued any time free <br/>-flops review. Further, as described in detail below, the present invention creates a "recording" of flops review and purchased programs. This record does not expire expeditiously in such a way as to aid the Pirates.

[0025] The arbitrary advantages of time Furipu review in order to prevent abduction service, confidentiality processor 20 of the present invention (FIG. 1), the time interval of program segments that may be viewed without buying reliably Restrict to To accomplish this, during any time Furipu review time
The interval (ie, the fixed time interval described above) is the unit of the working key epoch (ie, the working key epoch ).
- is maintained in the epoch units). The security processor 20 counts the number of generated free working keys. This count reaches the limit established by the maximum AFP time 82 (FIG. 4), "can be a Furipu review purchase or obtain" authority-like <br/> status of services,
It is changed to state that "only purchase possible" from the state of. The AFP time interval is one of the program attributes used when generating the program key . Thus, the AFP time interval cannot be changed without changing the program key itself , which protects the correct decoding of the program.

[0026] As described above, the apparatus of the present invention, to create a record of each of programs to or purchase the flop Les views <br/> over. Once a user chooses to watch AFP,
"Flops of view record" is made with secret protection processor 20 to determine the number of free working keys that are acceptable, to maintain the real-time counter in order to expire the record when the event or program has been completed. The timer must keep running if the receiver is tuned to the scrambled or encrypted waveform, so that the recording
Expires at a unique time. If the AFP record expires early,
You can take the second Furipu review time interval.
If this record expires late, there is no harm,
The number of new work that you can review it, while this record after the end of the program is present, is reduced.

According to the present invention, up to N records are maintained . Each record, any <br/> time selected by the user represents a Furipu review "flop review recording", or a program that has been purchased by the user "purchase record"
Or an inactive (null) record. In addition, according to the present invention, since the flops of view records are overwritten so as to provide a purchase record, event
With the exception of legitimate purchases of ( or other purchasable services ) , it is not possible to erase the preview record of a given event before the event has ended. Typically, a user requests a Furipu review, then, decide whether or not to purchase the event based on this Furipu review. If purchased event, up review record is maintained until the end of the event other than the other service is overwritten been purchased. It decides that the user to buy the event, up review record is changed to a purchase record.

[0028] The process that does not erase the flops of view recorded before the event is completed, it is an essential feature of the present invention. Step
If only review recorded is stored in the column of the first-in-first-out (FIFO), a new record is added, it may be old record disappears. So, the user, in order to <br/> this column filled, as viewed repeatedly Furipu review limited more by view briefly its and scans the several programs, then the desired other Furipu review of the program
Return to watch . In this case, once the flop review record is created by each of the flop review record of all events Ru are maintained, it is previously eliminated.

[0029] In addition, according to the present invention, the purchase of the program, priority is given to the provision of Furipu review. N available programs
Review / purchase all of the recording is active, if at least one recording is holding the AFP, secret protection processor 20, use original "purchase possible" service called
Indicates the enabled state. The reason for this is that, even if all of the available-flops of view / purchase record is used, is because one of the flops of view recording can be changed to a purchase record. Preferably, the flops of view records that have been changed in the purchase record, are those closest to expiration.

[0030] In addition, the evil ability to erase the flops of view record
From being use, it is important to carefully control the user opportunity to erase the flop review record. For example,
"Purchased" shows have been created by Pirates themselves. Accordingly, program purchase (e.g., purchase records) when overwriting Gapu review record, the present invention provides a variety of defenses and means. First,
Purchase to overwrite the preview record is debit
Includes secret protection transmission, the sum of the user of the decoder debit is increased by the cost of the program. The number of purchase, also, are counted in the method of the secret protection. Second, the purchase record itself remains in memory until the end of the purchased event. In this manner, the record is, until the end of the event, which was purchased, not the use of any other time Furipu review.

[0031] When the program to be selected for purchase is a program which is in-flops review record, this record is simply changed to the purchase record, this record will remain open. After the preview recording has been activated, the purchase of the program cannot be canceled. In this manner, the recording of the program is not erased. In addition, secret protection processor 20, to establish a purchase record of the final expiration time (or final annihilation time).
This minimum time is, for example, on the order of one hour, which defeats the potential intrusion by pirates attempting to expire the purchase record early.

[0032] any time Furipu review and program time between
Interval timing of, is held by secret protection processor 20. Real-time program expiration counter is, for this purpose, are held in secret protection processor. During program time
Septum and AFP interval is given by the unit of the working key epochs.

[0033] As described above, a set of records, are kept secret protection processor 20, to handle any time Furipu review and purchased programs. The N-flop review / program recording set is schematically shown in FIG. Records 90, 9
2, 94, 96 and 98 each contain the program attributes (including access requirements) of the particular event or program of interest for the recording. Flop review records, viewing the Furipu review
A count of the time remaining within the maximum AFP time interval for listening (eg, the number of free working keys remaining) is also maintained. Purchase records, created after Furipu review
Once formed, it can not be canceled.

The program attributes include the cost of the program, the access requirements the user must subscribe to in order to receive the program (eg, “tiers or tiers”),
Free preview at the start of the program for an arbitrary amount of time to see if FP is available , and if so, how many free working keys will be given for AFP
Or it may be utilized in place of the review or any time free-flops
It comprises information such as the free <br/> flop review boundaries, and various local access information at the start of a program when that may be utilized in addition to the review. As shown in FIG. 2, the access requirement is not confirmed by the one-way function 48 to confirm the use permission of the service.
As such , not all of this requirement can be changed without changing the program key used to generate the working key to decrypt the program. If the program key used for decryption is different from the one used for encryption, the decryption will fail. Including a maximum AFP time interval as an access requirement (eg, the number of free WKs allowed) will confirm that this parameter has been used and will allow the working key to be
Prevent deformation .

[0035] Each of the flop review / purchase record includes recording the effective flag, purchase flag, expiration timer counting, and also a portion of the program key to be used as the program <br/> identifier. The recording effective flag is, for example, a 1-bit flag,
Indicates whether the record is valid. This flag is
When set, indicates that the contents of the record are valid. When this flag is clear, the record is currently unused.

The purchase flag, records, indicating that became a purchase record on behalf of the flops of the view record. The working key epoch count is ignored if the purchase flag is set. The expiration timer counts the time elapsed in the program in a predetermined unit (for example, 2.56 seconds). Once the recording has expired, the recording valid flag is cleared.

[0037] part of the flops of view / purchase records program key <br/> over a given in, for example, a 5-byte clean program key, is used as a program identifier. Working key
Epoch count is a count of the number of working-key given during any time Furipu review.

[0038] as part of the induction of use permission state of the services that the user is required in order to be able to view the program, secret protection processor, a given program is responsibility
The case where it can be watched via the free preview at any time is determined. If even AFP has been provided for a particular program (as indicated by the recorded valid flag) all of the N available flop review / purchase record is in use, is Furipu review I can't.

The user is switching to a channel to provide AFP
A preview record is created each time switching is performed, but such an operation is not suitable. The reason for this is that, switch the user is in a different
To Yan'neru switched in succession (this behavior, "Chang
Known as “channel surfing”
) , Because the program that provides the AFP is continually encountered, and the N available records are quickly exhausted. Thus, the user interface 26 (FIG. 1) of AFP
It would give the option to view AFP when use is possible in the user, to will give an indication of the amount of free preview time remaining in the program to a user, furthermore, the program start time of the free preview (program flop les provide views) and between the poles first limited time interval portion
Providing any time Furipu review would handle the case where interrelated. In the preferred embodiment, the user interface is provided via a screen display on the user's television 28. Such generation on a screen display is well known in the art.

[0040] In general, the screen display is available when determining the secret protection processor that AFP in the acquired program is available. The user interface is a collection of text messages that define the AFP selection screen. When the user selects AFP, the user interface informs the security processor 20 of this and free access is allowed for up to AFP time.
Until the interval is received. In an alternative embodiment, the AFP is automatically received when sufficient time has elapsed after the user switched to a particular service.

[0041] To process the possible collision between the Furipu review and any time Furipu review at program start, it is preferable to be reinforced with various rules.
First, the program is in Furipu review at program start (or, during the previous epoch) when it is acquired, it should be ignored that the AFP is provided. User, and choose not to the purchase of the program, the user, to encounter the same program in the time after the Furipu review of the program at the start <br/> has been completed (in other words, another of the program and its program Switch to
That later returns to the program), AFP may be provided.
Second, programs purchased during the AFP time interval are never canceled. Once a purchase has been made during the AFP time interval , this purchase cannot be changed.

FIGS. 6 and 7 are provided in accordance with the present invention.
It is a flowchart illustrating a process of any time Furipu review. The routine begins at box 100,
In box 102, the working key epoch message is obtained. The WKE message identifies the WKE count within the current program epoch. In box 104, the program
A pre -key message is obtained. As shown in FIG. 2, the program pre -key is needed to generate a working key and a program key for a user authorized to use the service. Box 106 provides the user with permission to receive the program and all AFPs assigned to the program.
When the permission is granted , the user's permission to use the service is calculated. In box 108, if the user has been granted permission to receive the program,
A determination is made as to whether the user has wished to purchase the program. If so, a purchase record is made in box 110. In box 112,
Making a purchase record stores the incomplete portion of the clean program key (output from one-way function 48 of FIG. 2). This clean program key is used in one-way function 52 (FIG. 2) to derive the required working key, as shown in box 114.

[0043] While the working key is generated, in box 116, a determination is made as to whether the program epoch has ended is made. If not, the working key guidance is continued and boxes 114 and 1
The process loops with the program 16 until the program epoch ends. At the end of the program epoch, the purchase record is erased as shown by box 118. This routine
Next, the process ends at box 120.

If the program has not yet been purchased by a user authorized to use the service , the routine:
From box 108 to box 122, a determination is made as to whether the program epoch has ended. If so, the routine ends at box 120. If the program has not been completed, whether it is possible to use any time Furipu review, determination is made. If not, the routine returns to box 108.

[0045] If the AFP is available in the program (e.g., whether AFP count is not zero, or separate as indicated by "AFP Available <br/>ability" bit), the user Furipu review A determination is made at box 126 as to whether to make a request to view. If an AFP is requested, the routine proceeds to box 128 in FIG. In box 128, flops review recording is made. Next, at box 130, the AFP expiration counter (AEC) is initialized. In box 132, the clean program key is AFP
Stored together with the count. The AFP count is decremented with each working key, giving a record of the time remaining in the maximum AFP time interval (ie, the amount of time left for the viewer to watch a free program).

At box 134, a working key is created and the AFP count is decremented. Next, the program expiration time
Calculated directly from the current working key epoch, as shown in box 136. This way, AF
The expiration of the P record is dynamically recalculated for each working key. In particular, the variable M is calculated. Here, M = (AFP boundary−current WKE count). Next, M is converted to real time using simple scaling, and if the result is determined to be greater than the AEC in box 138, the AEC calculates the expiration time calculated in box 140. Time and
Overwritten . This destroys the preview record,
Extend AEC to prevent Pirates from trying to shorten AEC to get additional AFP for programs. AEC
There are tested, if necessary, after being overlaid, in box 14 4, whether AFP maximum time interval has expired (i.e., a zero number of free working keys flop review is reduced Is determined). If so, the use of AFP beyond the program's maximum AFP time interval is not allowed (box 152). Also, at box 146, a determination is made as to whether the AFP boundary has been crossed. AFP boundary is a working key epoch count representing the boundary, beyond this boundary, any time Furipu review is not allowed. As mentioned above, this parameter is used when generating the program key.
By including this in the program attributes used,
Confirmation of permission to use the free preview is performed .

After passing the AFP boundary, after the AFP boundary of the program
Not permitted also the use of any of AFP (box 15
2). On the other hand , at box 148, a determination is made as to whether the user has exited AFP. If not, the routine waits for the next working key epoch (box 149), and then a new working key is created in box 134. The routine then continues until the maximum AFP time interval expires, or crosses an AFP boundary, or until the user terminates AFP. At the end of AFP by the user, the current AFP time interval count will be incremented until the program is purchased, or
This is performed until the end of the program epoch or until the AFP is requested again. AFP interval count, a user, during a program, AFP boundary before, can be up AFP time interval to again utilize any time Furipu review until expiration.

[0048] AFP time after the user has terminated the AFP between
Or holding the septum counting, or Do AFP use is permitted after the maximum AFP interval has passed or AFP boundary has expired
And have, the routine of FIG. 6 and 7, returns to box 108. Next, if the program epoch has not ended, the user can purchase the program or service.

In an alternative embodiment, (box 1 in FIG. 7)
Can be removed by 30 and 136 of the expiration time from the of) WKE 140 calculates and AFP expiry counter maintenance of simply setting a minimum flop review recording expiration time. For example, if the flop review records, once created, small
Can be maintained for at least 2 hours. This Pirates, every 2 hours, so it is impossible to take one or more AFP, Ru <br/> protect the program any time Furipu review. If the minimum flop review recording expiration time is longer than the typical program epoch of the longest, the method shown in method or 7, until the program epoch service represented by the recording of previewable services at active ends Can be used to prevent the expiration of a record of a service that is actively previewable.

It should be understood that the present invention provides:
And to provide a full <br/> Leap review available metered services over a communication network program. Potential program purchasers can be shown a limited number of short time intervals of movies or other programs for free, prompting them to purchase this service. The present invention improves upon the prior art where only the first part of a movie can be watched for free. In any time Furipu Les views <br/> over the present invention, up review is not limited in the first part of the service. Time interval Furipu review is variable, it can be included in the program by identifying the maximum AFP time interval as the program attributes. In the present invention, also, the user, after seeing a portion of the available Furipu review once can <br/> be view other parts of the Furipu review. The user, as long as it does not exceed the maximum AFP time interval, the Furipu review, it is <br/> be viewed separately any number of times.

Although the present invention has been described with reference to specific embodiments thereof, various changes and modifications may be made without departing from the spirit and scope of the invention as set forth in the appended claims. It will be understood to those skilled in the art that this can be done as appropriate.

[Brief description of the drawings]

FIG. 1 is a block diagram of the device of the present invention.

FIG. 2 is a block diagram illustrating the hierarchy of decoding used in accordance with the present invention.

FIG. 3 is a diagram showing different types of time- axis occurring
Indicates the length of the program epoch.

FIG. 4 is a schematic of one program epoch, showing the various boundaries contained therein and a working key epoch (WKE) sample during the program epoch.

Figure 5 is a schematic of the recording of various flop les <br/> view / programs to be maintained in accordance with the present invention.

Figure 6 is in accordance with the present invention, the first part of a flowchart showing the confirmation of the permission of the use of any time Furipu les <br/> view.

FIG. 7 is a continuation of the flowchart of FIG. 6;

Continuing the front page (72) Inventor Allen Schmeit, Poway, California, USA, Wild Grove Road, 14550 (72) Inventor Paul Moroney, Oliven Hein, California, United States 3411 (56) Reference Reference JP-A-63-234790 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04N 7/10 H04N 7/14-7/173 H04N 7/20-7/22

Claims (26)

(57) [Claims] 1. A method for providing a video service to a consumer via an information network, comprising: (1) recovering data from the information network indicating a program epoch of the video service; (2) Providing the video service on a pay-as-you-go basis during the program epoch, which is the maximum time interval from its start to its end allocated to the video service, (3) consuming without purchasing the video service To
There between a fixed time interval which is provided in the program in the epoch
If, at any time until the maximum preview time interval shorter than the fixed time interval, a step of allowing a preview of a portion of the video service, (4) the program epoch, a plurality of working key
The number of working key epochs, divided by epoch,
Use cryptography to verify that the
The maximum preview time using the allowed count of
Providing an interval ; and (5) protecting the maximum preview time interval with a cryptographically secure method to prevent the video service from being shown to consumers for longer than the maximum preview time interval; Consisting of: 2. The method of claim 1, further comprising: after previewing a portion of the video service, enabling a consumer to purchase the video service for viewing during the program epoch. How to become. 3. The method of claim 1 or 2 , wherein indicating to the consumer viewing the video service the amount of unused preview time intervals remaining during the fixed time interval. Maintaining the possible records, wherein the records are maintained by a cryptographically secure method. 4. A method according to any of claims 1 3, step maintains a record of a previous video service the consumer during a program epoch had previewed, and the consumer Prohibiting previewing the video service during the current program epoch when any part of the video service has been previewed during the previous program epoch. 5. The method of claim 4 , wherein the record of the service is maintained in a cryptographically secure manner. 6. A method according to any one of claims 1 to 5, the active records of previewable video services N
Simultaneously, wherein each of the records is a purchase record representing a previewable video service purchased by the consumer, or a preview representing a video service selected by the consumer during the preview. Recording, and preventing the expiration of the active recording of the previewable video service until the end of the program epoch for the video service represented by the recording. How to become. 7. The method of claim 6, further comprising the step of preventing erasure of any preview recording until the video service represented by the preview recording has ended. 8. The method of claim 6 , wherein when the video service represented by the preview record is purchased by a consumer, the step of changing the preview record to a purchase record; Preventing alteration of the purchase record obtained from the step. 9. The method of claim 8 , wherein erasing any preview record terminates a program epoch of a video service represented by the preview record, except for a change to an unchangeable purchase record. A step of preventing, until further comprising. 10. The method according to claim 6 , wherein any preview to the consumer is provided whenever all of the N previewable video service recordings are active. Rejecting. 11. A method according to any one of claims 1 to 10, further comprising the step, to inform the consumer whether the amount of preview time unused remains much in the video service . 12. The method according to claim 1 , wherein the fixed time interval is protected by a cryptographically secure method. 13. An apparatus for providing a preview of a service available for purchase via a communication network, comprising: (1) a first means for processing data received from the communication network, The data identifies a service that can be purchased, identifies an epoch in which the service is provided, indicates whether a preview is available for the service, and allows a consumer authorized to use the service to use the service. Or providing data necessary for generating a key for receiving a preview thereof, (2) responding to the first means when a preview is possible with the service. A second means for measuring a fixed time interval during the epoch when the preview is permitted, (3) A user working with said first and second means to allow a consumer to preview a portion of said service at any time during said fixed time interval, up to a maximum preview time interval less than said fixed time interval. An interface, wherein a consumer can also purchase the service at the user interface; and (4) decrypting the service during a preview and after purchasing the service. Means for responding to said first means. 14. The apparatus of claim 13 , further comprising: means for protecting the maximum preview time interval in a cryptographically secure manner. 15. The apparatus according to claim 13 or 14 , wherein an amount of unused preview time intervals left for the consumer who can view the service during the fixed time interval. Means for maintaining, in a cryptographically secure manner, a record indicating the following. 16. The apparatus according to claim 13 , wherein active recording of previewable services is simultaneously performed by N
Means for maintaining up to a number, wherein each of the records is a purchase record representing a previewable service purchased by the consumer, or a preview record representing a service selected by the consumer for a preview. And means for preventing the expiration of the active recording of the previewable service until the end of the program epoch of the service represented by the recording. 17. The apparatus of claim 16 , further comprising: means for preventing erasure of any preview record until a program epoch of the service represented by the preview record ends. 18. The apparatus according to claim 16 , wherein when the service represented by the preview record is purchased by a consumer, the preview record is changed to a purchase record, and the preview record is changed to a purchase record. Means for preventing the purchase record obtained by said means from being altered. 19. The apparatus of claim 18 , wherein erasure of any preview record, except for a change to a purchase record that cannot be changed, causes the program for the service represented by the preview record to be erased. Means for preventing until the end of the epoch. 20. Apparatus according to any one of claims 16 to 19 , wherein any additional preview to the consumer is performed whenever all of the N previewable service records are active. Or means for rejecting also previewable services. 21. Apparatus according to any of claims 13 to 20 , further comprising means for informing the consumer of the amount of unused preview time intervals remaining in the service. 22. The apparatus according to claim 13 , wherein the epoch is divided into a plurality of working key epochs, the working key epochs are counted, and use thereof is permitted. Wherein a count verified using cryptography is used to provide the maximum preview time interval. 23. The apparatus according to claim 13 , wherein at least a part of data indicating whether a fixed time interval can be previewed and whether a preview is available for the service is used. And means for confirming that the use has been authorized. 24. Apparatus according to any of claims 13 to 23 , wherein said fixed time interval is protected by a cryptographically-based secret protection method. 25. The method according to any of claims 1 to 12 , wherein providing a program pre-key and using the program pre-key to determine the fixed time interval. The method that further comprises. 26. Apparatus according to any of claims 13 to 24 , wherein said first means processes data including a program pre-key, said program pre-key being said fixed time interval. Used to determine the device.